Ray, Undulate

Raja undulata

Method of production — Caught at sea
Capture method — Beam trawl
Capture area — North East Atlantic (FAO 27)
Stock area — Celtic Sea and west of Scotland
Stock detail


Picture of Ray, Undulate

Sustainability rating five info

Sustainability overview

The Undulate Ray are classified as endangered by the IUCN. Scientists advise that no Undulate Rays should be caught and retained in this area. Because of the endangered status, we have automatically red-rated this species.


Undulate rays belong to the Rajidae family, which includes most of the skates and rays commonly found in British waters, and sold at fishmongers. The undulate ray is a medium sized shelf species growing to a maximum length of 100 cm and weight of 10 kg. The species has a maximum age of 20 years with size and age at maturity estimated at 75 cm and 9 years for females and 73 cm and 7.5 years for males. Eggs are laid from March to September. Undulate rays are at the northern edge of their range in UK waters. They form discrete populations isolated from other stocks, for example, on the southwest coast of Ireland, with occasional records in the English Channel. They are also present along the south coast of England.

Stock information

Criterion score: 1 info

Stock Area

Celtic Sea and west of Scotland

Stock information

Undulate ray populations in this area are considered as ‘depleted’.

Although they can be abundant in local patchy distributions, they are susceptible to localised depletion if there is too much fishing in that area. Scientists advise that there should be no targeted fisheries in 2017 and 2018 and it is likely that many undulate rays taken as bycatch in tangle nets. The species is assessed as Endangered (2009) by the IUCN.

A volunteer-led project have been using photo identification technology to learn more about undulate populations on the South Coast. They have learnt that Undulate Ray individuals are easily identifiable due to their individual markings revealing that undulate rays have high site fidelity (meaning they stay very close to their home). This new research enables better and more specific management for the species. To learn more about this project, please visit www.undulateray.uk.


Criterion score: 1 info

The EU had designated the undulate ray as a Prohibited Species for commercial fishing vessels in ICES areas 6, 7, 8, 9 and 10. This meant fishermen were prohibited from targeting, retaining, transhipping or landing the species in these areas. Tralee Bay is voluntarily closed to commercial fishing to protect regionally important elasmobranchs including the undulate ray. The undulate ray is a key marine species in the UK Biodiversity Action Plan (UK BAP). Undulate rays are managed under a minimum landing length, a 3 month ban on their landings during their breeding season, a code of good practice with stakeholders and requirements on how they are landed. The code of practice should be followed by fishermen to the greatest degree possible but greater enforcement is needed in fisheries to ensure these bans are effective: it has been recorded that enforcing a ban on tangle netting in Tralee Bay in Ireland is difficult and therefore, the species are at risk of overfishing.

Capture Information

Criterion score: 1 info

The Undulate Ray in this area has a very local distribution, mainly in Tralee Bay on the Southwest Irish coast. It is caught in significant amounts as bycatch in tangle net fisheries which target spiny lobster or near-shore mixed-trawl fisheries. To mitigate this, there is a prohibition on tangle-netting in and around Tralee Bay and its vicinity, but it is difficult to enforce. Further measures are required to reduce the impact on undulate rays in this area. In this area, scientists advise that all Undulate Rays in this caught area are released. Under current EU legislation, where a directed fishery for skates takes place, a mesh size in the cod-end of no less than 28cm is required and not less than 22cm in the rest of the trawl. There is a potential for damage to the seabed from trawling. Trawling is also associated with discarding of unwanted fish, i.e. undersized and, or non-quota and, or over-quota species.


Based on method of production, fish type, and consumer rating: only fish rated 2 and below are included as an alternative in the list below. Click on a name to show the sustainable options available.

Halibut, Atlantic (Farmed)
Halibut, Pacific
Sole, Dover sole, Common sole
Sole, Lemon
Turbot (Caught at sea)
Turbot (Farmed)


Marine Management Organisation. 2017. Undulate Ray commercial bycatch. Available at: https://www.gov.uk/government/publications/undulate-ray-commercial-bycatch;
ICES Advice 2016. Undulate ray (Raja undulata) in divisions 7.b and 7.j (west and southwest of Ireland. Available at: http://ices.dk/sites/pub/Publication%20Reports/Advice/2016/2016/rju-7bj.pdf;
Shark Trust; 2010. An Illustrated Compendium of Sharks, Skates, Rays and Chimaera. Undulate Ray. Available at: https://www.sharktrust.org/shared/downloads/id_guides/undulate_ray_st_id_guide.pdf

Scientific, Technical and Economic Committee for Fisheries (STECF) - 56th Plenary Meeting Report (PLEN-17-03); Publications Office of the European Union, Luxembourg.